1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Input driver for Microchip CAP11xx based capacitive touch sensors
4 *
5 * (c) 2014 Daniel Mack <linux@zonque.org>
6 */
7
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/interrupt.h>
11#include <linux/input.h>
12#include <linux/leds.h>
13#include <linux/of_irq.h>
14#include <linux/regmap.h>
15#include <linux/i2c.h>
16#include <linux/gpio/consumer.h>
17
18#define CAP11XX_REG_MAIN_CONTROL	0x00
19#define CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT	(6)
20#define CAP11XX_REG_MAIN_CONTROL_GAIN_MASK	(0xc0)
21#define CAP11XX_REG_MAIN_CONTROL_DLSEEP		BIT(4)
22#define CAP11XX_REG_GENERAL_STATUS	0x02
23#define CAP11XX_REG_SENSOR_INPUT	0x03
24#define CAP11XX_REG_NOISE_FLAG_STATUS	0x0a
25#define CAP11XX_REG_SENOR_DELTA(X)	(0x10 + (X))
26#define CAP11XX_REG_SENSITIVITY_CONTROL	0x1f
27#define CAP11XX_REG_CONFIG		0x20
28#define CAP11XX_REG_SENSOR_ENABLE	0x21
29#define CAP11XX_REG_SENSOR_CONFIG	0x22
30#define CAP11XX_REG_SENSOR_CONFIG2	0x23
31#define CAP11XX_REG_SAMPLING_CONFIG	0x24
32#define CAP11XX_REG_CALIBRATION		0x26
33#define CAP11XX_REG_INT_ENABLE		0x27
34#define CAP11XX_REG_REPEAT_RATE		0x28
35#define CAP11XX_REG_MT_CONFIG		0x2a
36#define CAP11XX_REG_MT_PATTERN_CONFIG	0x2b
37#define CAP11XX_REG_MT_PATTERN		0x2d
38#define CAP11XX_REG_RECALIB_CONFIG	0x2f
39#define CAP11XX_REG_SENSOR_THRESH(X)	(0x30 + (X))
40#define CAP11XX_REG_SENSOR_NOISE_THRESH	0x38
41#define CAP11XX_REG_STANDBY_CHANNEL	0x40
42#define CAP11XX_REG_STANDBY_CONFIG	0x41
43#define CAP11XX_REG_STANDBY_SENSITIVITY	0x42
44#define CAP11XX_REG_STANDBY_THRESH	0x43
45#define CAP11XX_REG_CONFIG2		0x44
46#define CAP11XX_REG_CONFIG2_ALT_POL	BIT(6)
47#define CAP11XX_REG_SENSOR_BASE_CNT(X)	(0x50 + (X))
48#define CAP11XX_REG_LED_POLARITY	0x73
49#define CAP11XX_REG_LED_OUTPUT_CONTROL	0x74
50
51#define CAP11XX_REG_LED_DUTY_CYCLE_1	0x90
52#define CAP11XX_REG_LED_DUTY_CYCLE_2	0x91
53#define CAP11XX_REG_LED_DUTY_CYCLE_3	0x92
54#define CAP11XX_REG_LED_DUTY_CYCLE_4	0x93
55
56#define CAP11XX_REG_LED_DUTY_MIN_MASK	(0x0f)
57#define CAP11XX_REG_LED_DUTY_MIN_MASK_SHIFT	(0)
58#define CAP11XX_REG_LED_DUTY_MAX_MASK	(0xf0)
59#define CAP11XX_REG_LED_DUTY_MAX_MASK_SHIFT	(4)
60#define CAP11XX_REG_LED_DUTY_MAX_VALUE	(15)
61
62#define CAP11XX_REG_SENSOR_CALIB	(0xb1 + (X))
63#define CAP11XX_REG_SENSOR_CALIB_LSB1	0xb9
64#define CAP11XX_REG_SENSOR_CALIB_LSB2	0xba
65#define CAP11XX_REG_PRODUCT_ID		0xfd
66#define CAP11XX_REG_MANUFACTURER_ID	0xfe
67#define CAP11XX_REG_REVISION		0xff
68
69#define CAP11XX_MANUFACTURER_ID	0x5d
70
71#ifdef CONFIG_LEDS_CLASS
72struct cap11xx_led {
73	struct cap11xx_priv *priv;
74	struct led_classdev cdev;
75	u32 reg;
76};
77#endif
78
79struct cap11xx_priv {
80	struct regmap *regmap;
81	struct input_dev *idev;
82
83	struct cap11xx_led *leds;
84	int num_leds;
85
86	/* config */
87	u32 keycodes[];
88};
89
90struct cap11xx_hw_model {
91	u8 product_id;
92	unsigned int num_channels;
93	unsigned int num_leds;
94	bool no_gain;
95};
96
97enum {
98	CAP1106,
99	CAP1126,
100	CAP1188,
101	CAP1203,
102	CAP1206,
103	CAP1293,
104	CAP1298
105};
106
107static const struct cap11xx_hw_model cap11xx_devices[] = {
108	[CAP1106] = { .product_id = 0x55, .num_channels = 6, .num_leds = 0, .no_gain = false },
109	[CAP1126] = { .product_id = 0x53, .num_channels = 6, .num_leds = 2, .no_gain = false },
110	[CAP1188] = { .product_id = 0x50, .num_channels = 8, .num_leds = 8, .no_gain = false },
111	[CAP1203] = { .product_id = 0x6d, .num_channels = 3, .num_leds = 0, .no_gain = true },
112	[CAP1206] = { .product_id = 0x67, .num_channels = 6, .num_leds = 0, .no_gain = true },
113	[CAP1293] = { .product_id = 0x6f, .num_channels = 3, .num_leds = 0, .no_gain = false },
114	[CAP1298] = { .product_id = 0x71, .num_channels = 8, .num_leds = 0, .no_gain = false },
115};
116
117static const struct reg_default cap11xx_reg_defaults[] = {
118	{ CAP11XX_REG_MAIN_CONTROL,		0x00 },
119	{ CAP11XX_REG_GENERAL_STATUS,		0x00 },
120	{ CAP11XX_REG_SENSOR_INPUT,		0x00 },
121	{ CAP11XX_REG_NOISE_FLAG_STATUS,	0x00 },
122	{ CAP11XX_REG_SENSITIVITY_CONTROL,	0x2f },
123	{ CAP11XX_REG_CONFIG,			0x20 },
124	{ CAP11XX_REG_SENSOR_ENABLE,		0x3f },
125	{ CAP11XX_REG_SENSOR_CONFIG,		0xa4 },
126	{ CAP11XX_REG_SENSOR_CONFIG2,		0x07 },
127	{ CAP11XX_REG_SAMPLING_CONFIG,		0x39 },
128	{ CAP11XX_REG_CALIBRATION,		0x00 },
129	{ CAP11XX_REG_INT_ENABLE,		0x3f },
130	{ CAP11XX_REG_REPEAT_RATE,		0x3f },
131	{ CAP11XX_REG_MT_CONFIG,		0x80 },
132	{ CAP11XX_REG_MT_PATTERN_CONFIG,	0x00 },
133	{ CAP11XX_REG_MT_PATTERN,		0x3f },
134	{ CAP11XX_REG_RECALIB_CONFIG,		0x8a },
135	{ CAP11XX_REG_SENSOR_THRESH(0),		0x40 },
136	{ CAP11XX_REG_SENSOR_THRESH(1),		0x40 },
137	{ CAP11XX_REG_SENSOR_THRESH(2),		0x40 },
138	{ CAP11XX_REG_SENSOR_THRESH(3),		0x40 },
139	{ CAP11XX_REG_SENSOR_THRESH(4),		0x40 },
140	{ CAP11XX_REG_SENSOR_THRESH(5),		0x40 },
141	{ CAP11XX_REG_SENSOR_NOISE_THRESH,	0x01 },
142	{ CAP11XX_REG_STANDBY_CHANNEL,		0x00 },
143	{ CAP11XX_REG_STANDBY_CONFIG,		0x39 },
144	{ CAP11XX_REG_STANDBY_SENSITIVITY,	0x02 },
145	{ CAP11XX_REG_STANDBY_THRESH,		0x40 },
146	{ CAP11XX_REG_CONFIG2,			0x40 },
147	{ CAP11XX_REG_LED_POLARITY,		0x00 },
148	{ CAP11XX_REG_SENSOR_CALIB_LSB1,	0x00 },
149	{ CAP11XX_REG_SENSOR_CALIB_LSB2,	0x00 },
150};
151
152static bool cap11xx_volatile_reg(struct device *dev, unsigned int reg)
153{
154	switch (reg) {
155	case CAP11XX_REG_MAIN_CONTROL:
156	case CAP11XX_REG_SENSOR_INPUT:
157	case CAP11XX_REG_SENOR_DELTA(0):
158	case CAP11XX_REG_SENOR_DELTA(1):
159	case CAP11XX_REG_SENOR_DELTA(2):
160	case CAP11XX_REG_SENOR_DELTA(3):
161	case CAP11XX_REG_SENOR_DELTA(4):
162	case CAP11XX_REG_SENOR_DELTA(5):
163	case CAP11XX_REG_PRODUCT_ID:
164	case CAP11XX_REG_MANUFACTURER_ID:
165	case CAP11XX_REG_REVISION:
166		return true;
167	}
168
169	return false;
170}
171
172static const struct regmap_config cap11xx_regmap_config = {
173	.reg_bits = 8,
174	.val_bits = 8,
175
176	.max_register = CAP11XX_REG_REVISION,
177	.reg_defaults = cap11xx_reg_defaults,
178
179	.num_reg_defaults = ARRAY_SIZE(cap11xx_reg_defaults),
180	.cache_type = REGCACHE_RBTREE,
181	.volatile_reg = cap11xx_volatile_reg,
182};
183
184static irqreturn_t cap11xx_thread_func(int irq_num, void *data)
185{
186	struct cap11xx_priv *priv = data;
187	unsigned int status;
188	int ret, i;
189
190	/*
191	 * Deassert interrupt. This needs to be done before reading the status
192	 * registers, which will not carry valid values otherwise.
193	 */
194	ret = regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL, 1, 0);
195	if (ret < 0)
196		goto out;
197
198	ret = regmap_read(priv->regmap, CAP11XX_REG_SENSOR_INPUT, &status);
199	if (ret < 0)
200		goto out;
201
202	for (i = 0; i < priv->idev->keycodemax; i++)
203		input_report_key(priv->idev, priv->keycodes[i],
204				 status & (1 << i));
205
206	input_sync(priv->idev);
207
208out:
209	return IRQ_HANDLED;
210}
211
212static int cap11xx_set_sleep(struct cap11xx_priv *priv, bool sleep)
213{
214	/*
215	 * DLSEEP mode will turn off all LEDS, prevent this
216	 */
217	if (IS_ENABLED(CONFIG_LEDS_CLASS) && priv->num_leds)
218		return 0;
219
220	return regmap_update_bits(priv->regmap, CAP11XX_REG_MAIN_CONTROL,
221				  CAP11XX_REG_MAIN_CONTROL_DLSEEP,
222				  sleep ? CAP11XX_REG_MAIN_CONTROL_DLSEEP : 0);
223}
224
225static int cap11xx_input_open(struct input_dev *idev)
226{
227	struct cap11xx_priv *priv = input_get_drvdata(idev);
228
229	return cap11xx_set_sleep(priv, false);
230}
231
232static void cap11xx_input_close(struct input_dev *idev)
233{
234	struct cap11xx_priv *priv = input_get_drvdata(idev);
235
236	cap11xx_set_sleep(priv, true);
237}
238
239#ifdef CONFIG_LEDS_CLASS
240static int cap11xx_led_set(struct led_classdev *cdev,
241			    enum led_brightness value)
242{
243	struct cap11xx_led *led = container_of(cdev, struct cap11xx_led, cdev);
244	struct cap11xx_priv *priv = led->priv;
245
246	/*
247	 * All LEDs share the same duty cycle as this is a HW
248	 * limitation. Brightness levels per LED are either
249	 * 0 (OFF) and 1 (ON).
250	 */
251	return regmap_update_bits(priv->regmap,
252				  CAP11XX_REG_LED_OUTPUT_CONTROL,
253				  BIT(led->reg),
254				  value ? BIT(led->reg) : 0);
255}
256
257static int cap11xx_init_leds(struct device *dev,
258			     struct cap11xx_priv *priv, int num_leds)
259{
260	struct device_node *node = dev->of_node, *child;
261	struct cap11xx_led *led;
262	int cnt = of_get_child_count(node);
263	int error;
264
265	if (!num_leds || !cnt)
266		return 0;
267
268	if (cnt > num_leds)
269		return -EINVAL;
270
271	led = devm_kcalloc(dev, cnt, sizeof(struct cap11xx_led), GFP_KERNEL);
272	if (!led)
273		return -ENOMEM;
274
275	priv->leds = led;
276
277	error = regmap_update_bits(priv->regmap,
278				CAP11XX_REG_LED_OUTPUT_CONTROL, 0xff, 0);
279	if (error)
280		return error;
281
282	error = regmap_update_bits(priv->regmap, CAP11XX_REG_LED_DUTY_CYCLE_4,
283				CAP11XX_REG_LED_DUTY_MAX_MASK,
284				CAP11XX_REG_LED_DUTY_MAX_VALUE <<
285				CAP11XX_REG_LED_DUTY_MAX_MASK_SHIFT);
286	if (error)
287		return error;
288
289	for_each_child_of_node(node, child) {
290		u32 reg;
291
292		led->cdev.name =
293			of_get_property(child, "label", NULL) ? : child->name;
294		led->cdev.default_trigger =
295			of_get_property(child, "linux,default-trigger", NULL);
296		led->cdev.flags = 0;
297		led->cdev.brightness_set_blocking = cap11xx_led_set;
298		led->cdev.max_brightness = 1;
299		led->cdev.brightness = LED_OFF;
300
301		error = of_property_read_u32(child, "reg", &reg);
302		if (error != 0 || reg >= num_leds) {
303			of_node_put(child);
304			return -EINVAL;
305		}
306
307		led->reg = reg;
308		led->priv = priv;
309
310		error = devm_led_classdev_register(dev, &led->cdev);
311		if (error) {
312			of_node_put(child);
313			return error;
314		}
315
316		priv->num_leds++;
317		led++;
318	}
319
320	return 0;
321}
322#else
323static int cap11xx_init_leds(struct device *dev,
324			     struct cap11xx_priv *priv, int num_leds)
325{
326	return 0;
327}
328#endif
329
330static int cap11xx_i2c_probe(struct i2c_client *i2c_client)
331{
332	const struct i2c_device_id *id = i2c_client_get_device_id(i2c_client);
333	struct device *dev = &i2c_client->dev;
334	struct cap11xx_priv *priv;
335	struct device_node *node;
336	const struct cap11xx_hw_model *cap;
337	int i, error, irq, gain = 0;
338	unsigned int val, rev;
339	u32 gain32;
340
341	if (id->driver_data >= ARRAY_SIZE(cap11xx_devices)) {
342		dev_err(dev, "Invalid device ID %lu\n", id->driver_data);
343		return -EINVAL;
344	}
345
346	cap = &cap11xx_devices[id->driver_data];
347	if (!cap || !cap->num_channels) {
348		dev_err(dev, "Invalid device configuration\n");
349		return -EINVAL;
350	}
351
352	priv = devm_kzalloc(dev,
353			    struct_size(priv, keycodes, cap->num_channels),
354			    GFP_KERNEL);
355	if (!priv)
356		return -ENOMEM;
357
358	priv->regmap = devm_regmap_init_i2c(i2c_client, &cap11xx_regmap_config);
359	if (IS_ERR(priv->regmap))
360		return PTR_ERR(priv->regmap);
361
362	error = regmap_read(priv->regmap, CAP11XX_REG_PRODUCT_ID, &val);
363	if (error)
364		return error;
365
366	if (val != cap->product_id) {
367		dev_err(dev, "Product ID: Got 0x%02x, expected 0x%02x\n",
368			val, cap->product_id);
369		return -ENXIO;
370	}
371
372	error = regmap_read(priv->regmap, CAP11XX_REG_MANUFACTURER_ID, &val);
373	if (error)
374		return error;
375
376	if (val != CAP11XX_MANUFACTURER_ID) {
377		dev_err(dev, "Manufacturer ID: Got 0x%02x, expected 0x%02x\n",
378			val, CAP11XX_MANUFACTURER_ID);
379		return -ENXIO;
380	}
381
382	error = regmap_read(priv->regmap, CAP11XX_REG_REVISION, &rev);
383	if (error < 0)
384		return error;
385
386	dev_info(dev, "CAP11XX detected, model %s, revision 0x%02x\n",
387		 id->name, rev);
388	node = dev->of_node;
389
390	if (!of_property_read_u32(node, "microchip,sensor-gain", &gain32)) {
391		if (cap->no_gain)
392			dev_warn(dev,
393				 "This version doesn't support sensor gain\n");
394		else if (is_power_of_2(gain32) && gain32 <= 8)
395			gain = ilog2(gain32);
396		else
397			dev_err(dev, "Invalid sensor-gain value %d\n", gain32);
398	}
399
400	if (id->driver_data == CAP1106 ||
401	    id->driver_data == CAP1126 ||
402	    id->driver_data == CAP1188) {
403		if (of_property_read_bool(node, "microchip,irq-active-high")) {
404			error = regmap_update_bits(priv->regmap,
405						   CAP11XX_REG_CONFIG2,
406						   CAP11XX_REG_CONFIG2_ALT_POL,
407						   0);
408			if (error)
409				return error;
410		}
411	}
412
413	/* Provide some useful defaults */
414	for (i = 0; i < cap->num_channels; i++)
415		priv->keycodes[i] = KEY_A + i;
416
417	of_property_read_u32_array(node, "linux,keycodes",
418				   priv->keycodes, cap->num_channels);
419
420	if (!cap->no_gain) {
421		error = regmap_update_bits(priv->regmap,
422				CAP11XX_REG_MAIN_CONTROL,
423				CAP11XX_REG_MAIN_CONTROL_GAIN_MASK,
424				gain << CAP11XX_REG_MAIN_CONTROL_GAIN_SHIFT);
425		if (error)
426			return error;
427	}
428
429	/* Disable autorepeat. The Linux input system has its own handling. */
430	error = regmap_write(priv->regmap, CAP11XX_REG_REPEAT_RATE, 0);
431	if (error)
432		return error;
433
434	priv->idev = devm_input_allocate_device(dev);
435	if (!priv->idev)
436		return -ENOMEM;
437
438	priv->idev->name = "CAP11XX capacitive touch sensor";
439	priv->idev->id.bustype = BUS_I2C;
440	priv->idev->evbit[0] = BIT_MASK(EV_KEY);
441
442	if (of_property_read_bool(node, "autorepeat"))
443		__set_bit(EV_REP, priv->idev->evbit);
444
445	for (i = 0; i < cap->num_channels; i++)
446		__set_bit(priv->keycodes[i], priv->idev->keybit);
447
448	__clear_bit(KEY_RESERVED, priv->idev->keybit);
449
450	priv->idev->keycode = priv->keycodes;
451	priv->idev->keycodesize = sizeof(priv->keycodes[0]);
452	priv->idev->keycodemax = cap->num_channels;
453
454	priv->idev->id.vendor = CAP11XX_MANUFACTURER_ID;
455	priv->idev->id.product = cap->product_id;
456	priv->idev->id.version = rev;
457
458	priv->idev->open = cap11xx_input_open;
459	priv->idev->close = cap11xx_input_close;
460
461	error = cap11xx_init_leds(dev, priv, cap->num_leds);
462	if (error)
463		return error;
464
465	input_set_drvdata(priv->idev, priv);
466
467	/*
468	 * Put the device in deep sleep mode for now.
469	 * ->open() will bring it back once the it is actually needed.
470	 */
471	cap11xx_set_sleep(priv, true);
472
473	error = input_register_device(priv->idev);
474	if (error)
475		return error;
476
477	irq = irq_of_parse_and_map(node, 0);
478	if (!irq) {
479		dev_err(dev, "Unable to parse or map IRQ\n");
480		return -ENXIO;
481	}
482
483	error = devm_request_threaded_irq(dev, irq, NULL, cap11xx_thread_func,
484					  IRQF_ONESHOT, dev_name(dev), priv);
485	if (error)
486		return error;
487
488	return 0;
489}
490
491static const struct of_device_id cap11xx_dt_ids[] = {
492	{ .compatible = "microchip,cap1106", },
493	{ .compatible = "microchip,cap1126", },
494	{ .compatible = "microchip,cap1188", },
495	{ .compatible = "microchip,cap1203", },
496	{ .compatible = "microchip,cap1206", },
497	{ .compatible = "microchip,cap1293", },
498	{ .compatible = "microchip,cap1298", },
499	{}
500};
501MODULE_DEVICE_TABLE(of, cap11xx_dt_ids);
502
503static const struct i2c_device_id cap11xx_i2c_ids[] = {
504	{ "cap1106", CAP1106 },
505	{ "cap1126", CAP1126 },
506	{ "cap1188", CAP1188 },
507	{ "cap1203", CAP1203 },
508	{ "cap1206", CAP1206 },
509	{ "cap1293", CAP1293 },
510	{ "cap1298", CAP1298 },
511	{}
512};
513MODULE_DEVICE_TABLE(i2c, cap11xx_i2c_ids);
514
515static struct i2c_driver cap11xx_i2c_driver = {
516	.driver = {
517		.name	= "cap11xx",
518		.of_match_table = cap11xx_dt_ids,
519	},
520	.id_table	= cap11xx_i2c_ids,
521	.probe		= cap11xx_i2c_probe,
522};
523
524module_i2c_driver(cap11xx_i2c_driver);
525
526MODULE_DESCRIPTION("Microchip CAP11XX driver");
527MODULE_AUTHOR("Daniel Mack <linux@zonque.org>");
528MODULE_LICENSE("GPL v2");
529